.Less Error Message with Matrix Visual

[Joe22]

I have added everything from

https://github.com/microsoft/Powerbi-Visuals-SampleMatrix

to my VS Code and continue to get this error message when executing pbiviz start:

info Building visual...
error LESS style/visual.less : The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined

I have also made the the following npm installs with no success:
powerbi-visuals-tools@2.5.0
node@12.13.1
npm@6.12.1
typescript@2.3.3

Any suggestions?

[Anonymous]

Hi, I am facing the same problem! Does anyone have some news about this problem?

By the way, this is all of my code for the .less file: 

p {
    font-size: 20px;
    font-weight: bold;
    em {
        background: 'yellow';
        padding: 5px;        
    }
}

and this is the error: 

error LESS style/visual.less : The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined